Warming ocean layers melt polar ice sheets faster

Washington, July 4 (IANS) Warming of the ocean’s subsurface layers will melt portions of underwater Greenland and Antarctic ice sheets faster than previously thought, increasing sea levels more than projected.

The research, led by the University of Arizona, and based on 19 state-of-the-art climate models, suggests a new process which shows how global warming will accelerate the melting of the great ice sheets during this century and the next.

The subsurface ocean layers surrounding the polar ice sheets will warm substantially as global warming progresses, the scientists found. Besides being exposed to warming air, underwater portions of the polar ice sheets and glaciers will be bathed in warming seawater.

The subsurface ocean along the Greenland coast could increase as much as 2 degrees Celsius by 2100, according to an Arizona statement.

“To my knowledge, this study is the first to quantify and compare future ocean warming around the Greenland and the Antarctic ice sheets using an ensemble of models,” said lead author Jianjun Yin, assistant professor of geosciences at the University of Arizona.

“Ocean warming is very important compared to atmospheric warming because water has a much larger heat capacity than air,” Yin said. “If you put an ice cube in a warm room, it will melt in several hours. But if you put an ice cube in a cup of warm water, it will disappear in just minutes.”

Given a mid-level increase in greenhouse gases, researchers found the ocean layer 650 to 1,650 feet below the surface would warm, on an average, about 1 degree Celsius by 2100.

Jonathan T. Overpeck, co-author and professor of geosciences and Yin’s associate, said: “This does mean that both Greenland and Antarctica are probably going to melt faster than the scientific community previously thought.”